Tablet coating apparatus with weight monitoring

Abstract

This invention provides an apparatus and process for automatically coating solid pharmaceutical dosage forms, e.g., tablets. The apparatus comprises a coating pan, having a rotating means, e.g., motor and a weighing means, e.g., scales in combination with the pan and motor. A process controller is in electronic communication with both the pan motor and scales, for controlling the pan rotation and monitoring the weight of the coating pan contents. There is also provided a plurality of material containing reservoirs having conduit means communicating with the interior of the pan. The material containing reservoirs may also have weighing means, e.g, scales in combination with the reservoirs, which are also in electronic communication with the process controller. These reservoirs may contain a water supply, a coating syrup supply, color suspension supply, and polishing ingredients for use in coating the tablets. The process controller is pre-programmed to dispense the various coating ingredients in a precise sequence, while monitoring the coating weight of the tablets, whereby the entire coating process is automatically effectuated in one continuous operation.

What is claimed is: 
     
       1. An apparatus for automatic and continuous coating of solid pharmaceutical dosage forms comprising, a container means in rotatable communication with a rotating means,   the container means and the rotating means in operative relation to a weighing means for continuously determining the weight of the dosage forms and coating material in the container means,   one or more material reservoirs having conduit means in fluid communication with the interior of the container means, the reservoir also having flow control means to control the flow of material from the reservoir through the conduit means to the interior of the container means,   a process controller means in independent electronic communication with each of the rotating means, the weighing means, and the flow control means, for controlling the rotating of the container means and the flow of material from the reservoir in preprogrammed sequence based upon the changing weight of the tablets and tablet coating in the container means.   
     
     
       2. The apparatus according to claim 1 wherein at least one of material reservoirs is in operative relation to a reservoir weighing means, for continuously determining the weight of the material in the reservoir, with the reservoir also in electronic communication with the process controller means, for continuous monitoring of the weight of the material in the reservoir. 
     
     
       3. The apparatus according to claim 2, wherein one or more of the material reservoir conduits have one or more spray nozzles comprising a fluid outlet port in fluid communication with the reservoir conduit, a circumferencial air chamber about the fluid outlet port, the air chamber having an air inlet means, the fluid outlet port having an extendable portion beyond the air chamber, an elastomeric spray cap having a generally V-shaped wedge-like tip having an expandable apperature on the apex thereof, is in normally air tight engagement with the extended portion of the fluid outlet port, and fastening means for holding the spray cap in air-liquid sealed engagement with the end of the air chamber. 
     
     
       4. The apparatus according to claim 3, wherein the liquid inlet means of the air chamber has a check valve means. 
     
     
       5. The apparatus according to claim 4 wherein air supply means and air exhaust means are in fluid communication with the interior of the coating pan, and in electronic communication with the process controller means. 
     
     
       6. The apparatus according to claim 5, wherein cooling means are provided for cooling the external surface of the container means. 
     
     
       7. The apparatus according to claim 6, wherein the container means has on its internal surface baffel means. 
     
     
       8. The apparatus according to claim 7, wherein the baffel means are hollow and contain heat transfer means for transferring heat produced during coating to the external surface of the container means. 
     
     
       9. The apparatus according to claim 8, wherein the air supply means and the air exhaust means have air flow regulating means. 
     
     
       10. The apparatus according to claim 9, wherein the air supply means are further provided with heating means, temperature regulating means, and filtering means. 
     
     
       11. The apparatus according to claim 10, wherein the process controller means is provided with alarm means, whereby malfunctions in the process are signaled by the alarm means.